Method for manufacturing metal foam

Abstract

The present application provides a method for manufacturing a metal foam. The present application can provide a method for manufacturing a metal foam, which is capable of forming a metal foam comprising uniformly formed pores and having excellent mechanical properties as well as the desired porosity, and a metal foam having the above characteristics. In addition, the present application can provide a method capable of forming a metal foam in which the above-mentioned physical properties are ensured, while being in the form of a thin film or sheet, within a fast process time, and such a metal foam.

The invention claimed is: 
     
       1. A method for manufacturing a metal foam comprising:
 sintering a green structure, 
 wherein the green structure consists of a metal component and a salt, and optionally a binder and/or solvent, 
 wherein the metal component comprises a conductive metal in an amount of 55% by weight or more, 
 wherein the metal component is in a form of a powder, and 
 wherein the sintering of the green structure consists of applying an electromagnetic field to said structure so as to generate heat from the conductive metal in the metal component, 
 wherein the green structure is in a form of a film or a sheet having a thickness of 1,000 μm or less, 
 wherein the conductive metal is nickel, iron or cobalt, 
 wherein the conductive metal has an average particle diameter in a range of 10 μm to 100 μm, 
 wherein the salt is NaCl, KCl, K 2 CO 3 , KOH, NaOH, CsCl, CaCl 2 , MgBr 2 , MgCl 2 , Na 2 SiO 3 , Na 2 CO 3 , NaHCO 3 , NH 4 Br or NH 4 Cl, 
 wherein the salt has a particle diameter in a range of 30 μm to 250 μm, 
 wherein the electromagnetic field is formed by applying a current at a frequency in a range of 100 kHz to 1,000 kHz, and 
 wherein the green structure is formed by coating a mixture of the metal component and the salt on a substrate. 
 
     
     
       2. The method for manufacturing a metal foam according to  claim 1 , wherein the conductive metal has a conductivity at 20° C. of 8 MS/m or more. 
     
     
       3. The method for manufacturing a metal foam according to  claim 1 , wherein the green structure comprises, on the basis of weight, 30% by weight or more of the conductive metal. 
     
     
       4. The method for manufacturing a metal foam according to  claim 1 , wherein the green structure comprises 10 to 1,000 parts by weight of the salt, relative to 100 parts by weight of the metal component. 
     
     
       5. The method for manufacturing a metal foam according to  claim 1 , wherein the electromagnetic field is formed by applying a current in a range of 100 A to 1,000 A. 
     
     
       6. The method for manufacturing a metal foam according to  claim 1 , wherein the electromagnetic field is formed by applying a current at a frequency in a range of 100 kHz to 900 kHz. 
     
     
       7. The method for manufacturing a metal foam according to  claim 1 , wherein the electromagnetic field is applied for a time in a range of 1 minute to 10 hours. 
     
     
       8. The method for manufacturing a metal foam according to  claim 1 , further comprising removing the salt after sintering. 
     
     
       9. The method of  claim 1 , further comprising forming the metal foam having uniformly formed pores. 
     
     
       10. The method of  claim 9 , wherein the metal foam has a porosity in a range of about 40% to 99%.